(Adapted from applicant's abstract) This proposal is directed at developing a training program in the area of sleep and its disorders. There is growing evidence of the prevalence of sleep disorders in the American population and that problems related to inadequate sleep have a major impact on many aspects of our society. At a basic level, little is known about the fundamental mechanisms that control sleep and the function(s) of sleep. Thus, there is a major opportunity for scientific discovery about a fundamental biological process. One of the barriers that is recognized to advancing the knowledge base in this area is the paucity of investigators, both those engaged in basic research and in patient-oriented research. This application describes a training program that is based on the relatively unique faculty resources and structure at the University of Pennsylvania for support of research in sleep and its disorders (the Center for Sleep and Respiratory Neurobiology). The proposal describes three specific training aspects that are intended to complete the matrix for training opportunities at the University of Pennsylvania in the area of research in sleep/sleep disorders and circadian rhythm. These three aspects are the following: a) a graduate program in neurobiology of sleep and circadian rhythm. This will be based on the highly successful and well developed Neuroscience Graduate Program. The applicants will utilize, where appropriate, structures, courses and other resources developed by this group; b) a clinical investigator pathway that will provide an opportunity for house staff, primarily in the Department of Medicine, Department of Neurology or Department of Psychiatry to obtain a Ph.D. in neurobiology of sleep and circadian rhythm. This component will also utilize, where appropriate, the developed programs and courses of the Neuroscience Graduate Program; c) a postdoctoral training program for nurse investigators. This will be based on the preeminent School of Nursing at the University of Pennsylvania. There are members of the tenured faculty at the School who are funded investigators in outcomes of sleep disorders. This, together with the other rich intellectual resources at the School of Nursing, provides a unique opportunity to develop a much needed national program to train nurse investigators in this area. All of these components of the program will utilize the extensive resources for research that have been developed by the Center for Sleep and Respiratory Neurobiology at the University of Pennsylvania.